Interface tuning and stabilization of monoglyceride mesophase dispersions: Food emulsifiers and mixtures efficiency.

Several food surfactants were examined as possible efficient emulsifiers for liquid crystalline monolinolein-based particles and as alternative choices to the non-food-grade emulsifier conventionally used Pluronic® F127. We described a food emulsifiers' toolbox, investigating their ability to emulsify mesophases (stabilization capacity, particle size, zeta potential) and their impact on internal nanostructures (from swelling to drastic modifications). Among the selected surfactants, sucrose stearate (S1670) was found to be the best candidate for replacing in a long term F127 as an efficient stabilizer of lipid particles. The emulsification performed by mixing F127 with S1670 or sodium caseinate (NaCas), and S1670/NaCas helped to discriminate their respective role in the particles and so their efficiency for the stabilization. In case of S1670 as co-emulsifier no strong structural modification was observed, while using F127 (25wt% NaCas) an unexpected hexagonal mesophase was highlighted in self-assemblies. The evolution of zeta potentials by varying the mesophase and the emulsifier also informed about the distribution of co-surfactants in the particles. We thus reported submicronic nanostructured systems (from 100 to 350nm) that were fully food-grade and possibly contained limonene, with a surface charge from -70 to -5mV.